Anthracene‐Containing Binaphthol Chromophores for Light‐Emitting Diode (LED) Fabrication

Abstract

Non‐crystalline anthracene‐containing binaphthol chromophores were synthesized, characterized, and used in the fabrication of organic light‐emitting diodes (OLEDs). Specifically, the target molecules were 2,2′‐dihexyloxy‐1,1′‐binaphthol‐6,6′‐bisanthracene (BA1) and 2,2′‐dimethoxyy‐1,1′‐binaphthol‐6,6′‐bisanthracene (BA2). Molecules BA1 and BA2 provide amorphous solids, as determined by their glass‐transition temperature (Tg) measured by differential scanning calorimetry (DSC). Efficient multilayer OLEDs containing BA1 and BA2 were fabricated by evaporation techniques. Differences in the electroluminescence frequencies of these devices suggests that the degree of alkoxide substitution controls the mobility within the binaphthol material, and therefore the recombination region in the device. Compound BA2 can also be used to dope CBP ((4,4′‐bis(carbazol‐9‐yl)biphenyl)) in the fabrication of highly efficient OLEDs.

Binaphthyl‐Containing Green‐ and Red‐Emitting Molecules for Solution‐Processable Organic Light‐Emitting Diodes

“…[9,10] The non-planar binaphthyl unit, with its large dihedral angle and its twisted conformation, has proved to be a suitable moiety that yields a stable amorphous phase and results in good solubility. To date, binaphthyl-containing polymers, [11][12][13][14] dendrimers, [15,16] and small organic molecules [17][18][19] have already been widely used in chiral sensors, [20][21][22][23] unsymmetrical catalysis, [24][25][26][27] photochromic application, [28][29][30] and nonlinear optical materials; [31,32] but in recent years binaphthyl-containing materials have also been successfully employed as blue-emitter in electroluminescent (EL) devices. [11][12][13][14]17,18,[33][34][35][36][37][38][39][40] Yet, greenand red-emitting materials based on binaphthyl-containing molecules (BNCMs) are rarely reported so far.…”

Facile synthesis and properties of binaphthyl-containing blue light emitting materials

“…The onset potentials for oxidation of BNOAV, BNONV and BNOBPV were obtained, respectively, to be 1.0, 1.1, 1.2 V (vs. Ag wire), which were quite close to those of other compounds containing binaphthyl units [5][6][7][8][9]. On the other hand, the onset potentials for reduction were À1.6, À2.0, À2.1 V (vs. Ag wire).…”

“…Since Jen and coworkers synthesized the first binaphthylbased light-emitting materials in 1999 [5], there have been an increasing interest in synthesis of luminescent materials containing binaphthyl units [6][7][8][9]. It is well known that the dihedral angle between the two naphthalene rings ranges from 601 to 1201 in a binaphthyl unit.…”

Red Electrophosphorescence from a Soluble Binaphthol Derivative as Host and Iridium Complex as Guest

“…11,12 A hexyl chain was introduced at the 2 and 2′ positions to ensure good solubility. The carbazole unit was introduced at the 6 and 6′ positions using the Buchwald-Hartwig cross coupling.…”